Device for conducting postal articles, forms or the like



Oct. 29, 1963 c. J. VAN DALEN 3,108,801

DEVICE FOR CONDUCTING POSTAL ARTICLES, FORMS OR THE LIKE Filed June 27,1961 2 Sheefs-Sheet 1 Hi, I

IN VEN TOR.

E. J- YANDALEN. BY

AT T'YI Oct. 29, 1963' l c. J. VAN DALEN 3,108,301

' DEVICE FOR CONDUCTING POSTAL ARTICLES, FORMS OR THE LIKE Filed June27, 1961 2 Sheets-Sheet 2 FIG.2

IN V EN TOR.

[1i VAN DALEN. BY

.ATTY.

United States Patent Ian! 3,193,891 DiEVl CE FOR tJSNDUtITlNG PHSTALARTEQLES, FORMS 9R THE Eli Christiaan Johannes van Balen,Lei-:lscheinam, Netherlands, assignor to De taat tier Nederlanden, tenDene Vertegenwoordigd Door de Birecteur-Generaal der il oserijen,Telegrafie en Teiefonie, The Hague, Nether- Filed June 27, 1961, Ser.No. 12$,tlli4 Claims priority, application Netherlmds June 23, 1960 16Claims. (Cl. 271-57) The invention relates to a device for guiding onpostal articles, forms or the like, into which said articles ordocuments are fed from piles thereof, and which device takes them fromthe pile one by one and guides them successively on their way with apredetermined spacing between them.

A part of this device is disclosed in the prior co-pending US. patentapplication SN. 84,268, filed June 23, 1961, wherein letters or similarsheet articles are taken from a pile and moved along one by one by acontinuously driven conveyor belt in an erect position onto anotherconveyor belt which conveys them while still erect past a number ofprocessing stations and at certain points moves them into gutters orchutes to follow various further routes. In this prior deviceintroduction of double documents is prevented by a flexibly drivencounter-rotation roller at the inlet to the conveyor belt. Said devicehas the drawback that the spaces between successive letters can only beincreased to a usable value by giving the second conveyor belt for theirfurther transport a greater speed than the feeding conveyor belt, but bythen the space between one letter and a next longer-sized document willbe greater than the space between one letter and a next shorter-sizeddocument.

It is an object of this invention to provide a device which will produceuniform spaces between articles in such conveying systems, independentof the size or length of such articles within the limits of between 14and 22 centimeters set by law for the sizes of letters on postalarticles.

Generally speaking, this device according to this invention comprises acontinually running conveyor belt with a retractable elastic pressingdevice which presses the conveyor belt against the end of a pile ofarticles to frictionally move from said pile the end article or documentand move it past a switching device which causes the pressing device toretract when the leading edge of the document passes said switchingdevice, thereby releasing the conveyor belt from acting on the nextdocument in the pile until the trailing edge of the former documentpasses said switching device, and then said pressing device againpresses the conveyor belt against said next document to start it movingfrom the pile a uniformly spaced distance from the trailing edge of saidformer document.

Further according to the invention a small roller located between thebelts is permanently pressed by spring action against thecounter-rotation roller which causes documents loosely sliding forwardfrom the pile in the period when the pressing device has released thebelt from acting on the pile, to be returned to the pile.

In the embodiment to be described hereinafter the switching device maycomprise one or more photocells located along the belt connected tocorresponding relays which together control an electromagnet thatactuates the pressing device. The photocells receive light from sourcesof light placed opposite the photocells. When and as long as one of thelight beams is intercepted by a passing document, the pressing device isin its retracted position and, consequently, the supply or feeding ofdocuments from the pile is interrupted.

ice

By means of the device of this invention regular spaces can be obtainedbetween the documents. The length of these spaces can be determined byadjusting the distance between the counter-rotation roller and thephotocell located farthest therefrom. The number of photocells to beused depends on the spaces desired between the documents. If spaces aredesired shorter than the minimum length of a document, one photocellwill do. If longer spaces are desired, two or more photocells arerequired, since even the shortest document must control the switchingdevice from the moment it has entirely passed the counter rotationroller till the moment it has entirely passed the last photocell. Tothis end it is necessary that the distance between counter-rotationroller and first photocell, and between each adjacent pair of photocellsis slightly less than the length of the shortest document to beconducted by the device of this invention. 7

The invention will now be described in detail with reference to thedrawings, wherein:

FIG. 1 is a schematic plan diagram of one plan of the device accordingto this invention for conducting postal articles;

FIG. 2 is a perspective view of a specific device according to the plandiagram of FIG. 1;

FIG. 3 is a schematic wiring diagram of a control circuit for thepressing mechanism shown in FIGS. 1, 2 and 4; and

HG. 4 is an enlarged plan view of the pressing rollers of the deviceshown in F168. 1 and 2, and in dotted lines the retracted positionthereof.

In the diagram of FIG. 1 are shown a receptacle 10 for the pile, acontinually driven belt conveyor 20, a second belt conveyor 30co-operating with the belt conveyor 20, a counter-rotation roller 49, alever 50 bearing a small roller 51, the pressing-rollers 71 and '72- ofthe retractable elastic pressing device 79 and two light systems 3% and90, each comprising a source of light 8 1 and 9 1 and a photocell 82 and92.

FIG. 2 shows a more detailed view of these elements in which the beltconveyors 26 and 3e are twin belts 21, 22 and 31, 32 separated by aspace to let pass the light beams from sources 81 and 91. In thereceptacle 10- the documents D (FIG. 1) are permanently pushed by aforce 11, such as a spring (not shown) towards the counter-pressureplate 12. This plate is provided with two slots 13 and 14, throughwhich, according to the state of the electro-magnetically controlledrollers 71 and 72, the belts 21 and 2 2, can or cannot act on the end ofthe pile of documents D (see FIG. 1). Further there are thecounter-rotation roller 40, the lever 50 hearing the roller 51, whichalso lies between the two belts 21 and 22a, and the light beams of thesystems St and 99 of the sources of light 81 and 91 and photocells 82.and 92, from which the control of the pressure rollers '71 and 72 isderived.

The operation of the device is as follows:

The pile of letters or documents D placed in the receptacle 10 ispermanently pushed towards the conveyor belts 21 and 22. The firstletter D (see FIG. 2) is moved along by these belts 21 and 2a to thespace 23 and there fed between the belts 21 and 2.2 and acounter-rotation roller 40. This roller 40 is driven in a directioncontrary to the rotation it assumes when in contact with the conveyorbelts 21 and 22 by a slipping coupling adjusted so loose that in thecase of a reduced friction between the belts 21 and 2-2 and roller 49,it assumes this contrary rotation (as shown in the above mentionedco-pending application SN. 84,268) so that if two documents would slipbetween belts 2.1 arid 2,2 and roller 40, the roller'4tl would push thesecond letter erroneously removed from the pile back onto the pile, andonly the first document would be moved forward. Before this document D29 has entirely left the counter rotation roller 40, the leading edge ofthe document D reaches the first photocell 32 and intercepts the beam oflight 83 for this photocell 32. The current through the photocell ceasesto flow and relay A in FIG. 3 releases and closes its break contact a.The electromagnet E is energized and attracts the rollers 71 and 72mounted on a steel rod 73, as a result or which the conveyor belts 2'1and 22 recede between the slots 13 and 14 of plate 12. During thisinterruption in the beam 83 to the photocell 82 by the document D, thisdocument is moved forward and is seized between the belts ZL-ZZ; and3l-32. When the document D has almost entirely passed the photocell 82,the leading edge of the document D reaches the photocell 92,intercepting the light beam 93 for this cell, so that the current flowthrough relay B in FIG. 3 is interrupted. Relay B releases and closesits break contact b. This contact takes over the function of contact a,so that also after the trailing edge of the document D has passedphotocell 62 and relay A has attracted its armature again, theelectromagnet E retracting rollers 71 and 72 remains energized.

When now the trailing edge of the document D reaches photocell 92, thiscell receives light again, relay B reenergizes and the circuit of theelectromagnet E is broken. The rollers 71 and 72 then push the belts 2iand 22. again through the slots 13 and 14 of plate 12 against the pile,and a fresh or the next document D is removed therefrom. This documentwill follow the preceding one D at a distance corresponding to thedistance between the counter rotation roller 4e and the photocell 92.Thus the distance between the successive documents can be fixed by thechoice of the distances between the roller 4% and the photocells 82 and2, independently of the size of the document.

In the withdrawn condition of the pressure rollers '71 and 72 it ispossible that documents may erroneously slide forward from the pile. Toavoid this the small roller 51 (see FIG. 4), co-operating with thecounter-rotation roller 40 has been provided. This roller 51 is mountedon a lever 56', which has its fulcrum in 52. By means of a spring 53 theroller 51 is pressed, between two belts 21 and 22, against thecounter-rotation roller 40. In the case of withdrawn belts 2A1 and 22the latter roller 44} will assume the counter-rotation imparted to it bythe slipping coupling (shown in said previously mentioned. priorco-pending application). Thus letters loosely moving forward from thepile will soon impinge on the rollers 40 and 51, which shoot them backonto the pile.

While I have illustrated and described what I regard to be the preferredembodiment of my invention, nevertheless it will be understood that suchis merely exemplary and that numerous modifications and rearrangementsmay be made therein without departing from the essence of the switchingmeans operated by said removed sheet for controlling the retraction andengagement of said reciprocal means to prevent the engagement of thenext sheet in said pile until said removed sheet is moved past saidswitching means by said conveyor belt. 2. A device according :to claim 1wherein said reciprocal means comprises a roller, and electromagneticmeans controlled by said switching means for moving said roller againstthe inside of said belt towards and away from the end of said pile.

3. A device according to claim 1 wherein said switching means comprisesalight source producing a beam and a photoelectric cell responsive tosaid beam and located so that said removed sheet interrupts said beambetween said source and said cell for controlling said reciprocal means.

4. A device according to claim 1 including counterrotating roller meansnear the end of said pile for returning sheets to said pile which may beerroneously removed while said reciprocal means is retracted, andincluding means for overriding said returning means when said reciprocalmeans is opera-ted to frictionally engage said belt with a sheet to beremoved from said pile.

5. A device according to claim 4 wherein said means for overriding saidroller means comprises a slipping couplin for driving said roller means.

6. A device according to claim 4 wherein said overriding means comprisesa second roller means resiliently pressed against said counter-rotatingroller means.

7. A device for conducting postal articles successively alon a path at apredetermined distance apart from a pile of said articles comprising:

(a) a conveyor belt continuously moving transversely of the end of saidpile,

(b) reciprocal means for intermittently retracting and frictionallyengaging said belt with the article at the end of said pile for itsremoval from said pile and movement along said path,

(0) switching means operated by said removed article for controlling theretraction of said reciprocal means to prevent the engagement of thenext article in said pile until the removed article is moved past saidswitching means by said conveyor belt,

(d) counter-rotating roller means located near the end of said pile andfacing said conveyor belt for returning articles to said pile which maybe removed erroneously from said pile by said belt while said reciprocalmeans is retracted, and

(0) means for overriding said counter-rotating roller means when saidreciprocal means is operated to frictionall-y engage said conveyor beltwith an article from said pile for movement along said path.

8. A device according to claim 7 wherein said means for overriding saidroller means comprises a slipping coupling for driving saidcounter-rotating roller means.

9. A device according to claim 7 wherein said conveyor belt comprises apair of parallel spaced belts.

10. A device according to claim 9 wherein said means for overriding saidroller means includes a second roller means frictionally engaging saidcounter-rotating roller means between said pair of spaced belts.

11. A device according to claim 9 wherein said switching means includesmeans projecting between said belts for interruption by said article.

12. A device according to claim 11 wherein said switching meanscomprises an electric light source producing said projecting means and aphotoelectric cell responsive to said projecting means.

13. A device according to claim 7 wherein said reciprocal meanscomprises a pair of rollers inside said belt, one opposite said pile andthe other opposite said counterrotating roller means, andelectro-magnetic means controlled by said switching means for retractingboth of said rollers.

14. A device according to claim 7 including a plurality of saidswitching means spaced along said path at distances slightly less thanthe shortest article to be moved along said path for maintaining saidreciprocal means retracted as long as said article is in contact withone of said switching means.

15. A device for removing one sheet at a time from a pile of saidsheets, composing:

(a) reciprocal means for intermittently retracting and frictionallyengaging one side of the end sheet of said pile for its removal fromsaid pile,

(b) counter rotating roller means located adjacent the end of said pileand facing said engaging means for returning additional sheets to saidpile which may be removed erroneously from said pile when said engagingmeans is engaging a sheet, and

(c) a second roller means pressed against said counter rotating rollermeans for preventing the erroneous removal of a sheet from said pilewhen said engaging means is not engaging a sheet.

16. A device for conducting sheets successively along a path at apredetermined distance apart from a pile of said sheets, comprising:

'(a) a conveyor belt continuously moving away from the end of said pile,

(b) reciprocal means for intermittently retracting and frictionallyengaging one side of the end sheet of said pile for its removal firomsaid pile and for movement by said conveyor along said path,

(a) switching means operated by said removed sheet for controlling thereciprocal engaging means to prevent the removal of the next sheet fromsaid pile until the removed sheet is a predetermined distance firom saidpile,

(d) counter rotating roller means located near the end of said pile andfacing said reciprocal engaging means for returning additional sheets tosaid pile which may be removed erroneously from said pile when saidreciprocal engaging means is engaging a sheet, and

(e) a second roller means pressed against said counter rotating rollermeans for preventing the erroneous removal of a sheet from said pilewhen said reciprocal engaging means is not engaging a sheet.

References Cited in the file of this patent UNITED STATES PATENTSBreuers July 17, 1962

1. A DEVICE FOR CONDUCTING SHEETS SUCCESSIVELY ALONG A PATH AT APREDETERMINED DISTANCE APART FROM A PILE OF SAID SHEETS, COMPRISING: (A)A CONVEYOR BELT CONTINUOUSLY MOVING TRANSVERSELY OF THE END OF SAIDPILE, (B) RECIPROCAL MEANS FOR INTERMITTENTLY RETRACTING ANDFRICTIONALLY ENGAGING SAID BELT WITH THE SHEET AT THE END OF SAID PILEFOR ITS REMOVAL FROM SAID PILE AND MOVEMENT BY SAID CONVEYOR ALONG SAIDPATH, AND (C) SWITCHING MEANS OPERATED BY SAID REMOVED SHEET FORCONTROLLING THE RETRACTION AND ENGAGEMENT OF SAID RECIPROCAL MEANS TOPREVENT THE ENGAGEMENT OF THE NEXT SHEET IN SAID PILE UNTIL SAID REMOVEDSHEET IS MOVED PAST SAID SWITCHING MEANS BY SAID CONVEYOR BELT.